1. Field of the Invention
The present invention relates to an image capturing apparatus capable of controlling a recording speed of recording media during a capture of a moving image.
2. Description of the Related Arts
There is a widespread use of a digital camera in which a signal output from a solid-state imaging device such as a CCD is converted into image data of digital signal form by an A/D converter, and the image data is recorded in a recording medium such as a built-in memory or a removable memory card. This type of digital camera has a moving image capture function as well as a still image capture function.
In the digital camera, field images are sequentially output from the CCD at a constant frame rate (e.g. 30 frames/sec.) during the capture of the moving image. The field images are temporarily stored in a buffer memory. Subsequently, the filed images are read out from the buffer memory, and recorded in the recording media after various kinds of image processing including the YC conversion and the compression processing are applied thereto (see Japanese Patent Laid-Open Publications No. 2004-56741).
In the moving image capturing, many field images are recorded in the recording media, and the amount of the image data output from the CCD becomes very large. In some models or types of recording media, the recording (writing) operation might be so slow that the recording media may possibly store unwatchable moving images in which the frames are missed in parts.
As a method for solving the above problem, it is considered that a high frequency system clock for operating a CPU, the buffer memory, the recording media, and so forth is used to accelerate a transfer speed of the image data (a reading speed of the buffer memory, a recording speed of the recording media). However, if the high frequency system clock is used, it causes another problem that the power consumption is increased.